Toad tunnels require ongoing maintenance to remain effective. Blocked or flooded tunnels fail to protect amphibians and represent wasted conservation investment.
A toad tunnel that is blocked or disconnected from functional drift fencing provides no welfare benefit — toads continue to cross on the road surface and die at the same rate as before installation. The welfare value of tunnels is entirely dependent on ongoing maintenance commitment from landowners, highways authorities or volunteer groups. Habitat management around tunnel entrances that maintains damp leaf litter and low vegetation provides attractive conditions that encourage toads to enter tunnels. Annual surveys before migration season to check tunnel and fence condition are essential to protect the investment and the amphibians.